Energy storage device

ABSTRACT

A surface mount energy storage device in the form of a supercapacitor ( 1 ) includes a generally rectangular folded prismatic housing ( 2 ) and two energy storage elements (not shown) that are sealingly contained within the housing ( 2 ) and which are connected in series. A mount, in the form of an integrally formed tinned metal frame ( 3 ), extends about and captively retains housing ( 2 ) in the folded configuration shown. Two terminals, in the form of elongate contacts ( 4, 5 ) extend from the energy storage elements and terminate outside housing ( 2 ) for allowing external electrical connection to the elements.

FIELD OF THE INVENTION

[0001] The present invention relates to an energy storage device.

[0002] The invention has been developed primarily for supercapacitorsand will be described hereinafter with reference to that application.However, it will be appreciated that the invention is not limited tothis particular field of use and is also applicable to other energystorage devices such as batteries, capacitors, fuel cells and the like.

DISCUSSION OF THE PRIOR ART

[0003] Hitherto, a variety of capacitors and supercapacitors and otherenergy storage devices have been devised. However, particularly forsupercapacitors, the technology has not been well understood anddevelopment has been hindered through the need to use:

[0004] 1. Electrolytes that are volatile, corrosive and easilycontaminable;

[0005] 2. Expensive and labour intensive manufacturing techniques thatadd significantly to the unit cost of the supercapacitors;

[0006] 3. Expensive materials and handling procedures that also addsignificantly to the unit cost of the supercapacitors;

[0007] 4. Rigid packaging;

[0008] 5. Bulky packaging; and

[0009] 6. Packaging that is extremely susceptible to leakage.

[0010] All these factors generally contribute to wide performancevariations between devices that are made with the same process.Moreover, the cost of the resultant supercapacitors limits the range ofproducts to which they can be commercially applied.

[0011] Any discussion of the prior art throughout the specificationshould in no way be considered as an admission that such prior art iswidely known or forms part of common general knowledge in the field.

BRIEF DESCRIPTION OF THE INVENTION

[0012] It is an object of the present invention, at least in thepreferred embodiments, to overcome or substantially ameliorate one ormore of the disadvantages of the prior art.

[0013] According to a first aspect of the invention there is provided asupercapacitor including:

[0014] a first electrode;

[0015] a separator sheet that is captively retained to the firstelectrode;

[0016] second electrode being abutted against the separator sheetwhereby the electrodes are maintained in a spaced apart configuration;

[0017] a housing for containing the electrodes, the separator sheet andan electrolyte for allowing ionic conduction between the electrodes; and

[0018] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0019] According to a second aspect of the invention there is provided asupercapacitor including:

[0020] a first electrode;

[0021] a second electrode disposed adjacent to the first electrode;

[0022] a separator being captively retained only to the second electrodefor maintaining the electrodes in a spaced apart configuration;

[0023] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0024] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0025] According to a third aspect of the invention there is provided asupercapacitor including:

[0026] a first electrode;

[0027] a second electrode disposed adjacent to the first electrode;

[0028] a separator being captively retained to the second electrode andnot the first electrode for maintaining the electrodes in a spaced apartconfiguration;

[0029] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0030] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0031] According to a fourth aspect of the invention there is providedan energy storage device including:

[0032] a first electrode;

[0033] a second electrode disposed adjacent to the first electrode;

[0034] a separator being retained to the second electrode under tensionfor maintaining the electrodes in a spaced apart configuration;

[0035] housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0036] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0037] According to a fifth aspect of the invention there is provided anenergy storage device including:

[0038] a first electrode;

[0039] a second electrode disposed adjacent to the first electrode, thesecond electrode having at least one edge;

[0040] a separator having two opposed faces that sandwich the secondelectrode and which are abutted and joined together at the edge formaintaining the electrodes in a spaced apart configuration;

[0041] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0042] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0043] Preferably, the second electrode includes at least three edgesand the opposed faces are abutted and joined together at all thoseedges. More preferably, the opposed faces are abutted and joinedtogether along less than the entirety of each edge.

[0044] Preferably, the separator includes two porous sheets that areperipherally connected to each other.

[0045] Preferably also, the second electrode is a sheet electrode havinga first side, a second side that is opposed to the first side, and acommon peripheral edge joining the first side and the second side, andthe separator includes:

[0046] a first porous sheet that extends across the first side and whichincludes at least one first edge that protrudes beyond the commonperipheral edge; and

[0047] a second porous sheet that extends across the second side andwhich includes at least one second edge that protrudes beyond the commonperipheral edge wherein the first and second edges are connected forcaptively retaining the separator to the second electrode.

[0048] In a preferred form, the connection of the first and the secondedges involves bonding those edges together. More preferably, thebonding includes heat welding those edges together. In alternativeembodiments, however, the bonding includes adhering those edgestogether. In still further embodiments the bonding includes heat sealingthe edges together.

[0049] Preferably, the device includes:

[0050] a like plurality of first and second electrodes that arealternated with each other and contained within the housing, all thefirst electrodes being electrically connected to one of the terminalsand all the second electrodes being connected to the other terminal; and

[0051] a plurality of like separators each extending about a respectivesecond electrode to maintain that electrode in a spaced apartconfiguration from the or each adjacent first electrode.

[0052] Preferably, also, the second electrode is formed from acontinuous longitudinally extending conductive sheet having a pluralityof spaced apart transverse slots and the porous sheets are connected toeach other through the slots. More preferably, the conductive sheet iscut transversely through the slots to provide a plurality of separatesub-electrodes. Even more preferably, the slots are equallylongitudinally spaced apart and the sub-electrodes are substantiallyequivalent.

[0053] In a preferred form, the first electrode includes a plurality ofseparate sub-electrodes that are stacked together alternately with acorresponding plurality of sub-electrodes of the second electrode. Morepreferably, each sub-electrode includes an electrode area and thesub-electrodes of the first and the second electrodes include respectivefirst and second tabs extending outwardly from the correspondingelectrode areas. Even more preferably the sub-electrodes are stackedsuch that the electrode areas of all the electrodes overlap and thefirst tabs overlap each other and are electrically connected and thesecond tabs overlap each other and are electrically connected, wherebythe first tabs and the second tabs do not overlap each other.

[0054] Preferably, the separator includes two flexible sheets each ofwhich define one of the opposed faces. More preferably, the sheets areporous. Even more preferably, the opposed faces, in use, are maintainedin tensioned abutment against the second electrode.

[0055] According to a sixth aspect of the invention there is provided amethod of forming a supercapacitor, the method including:

[0056] providing a first electrode;

[0057] captively retaining a separator sheet to the first electrode;

[0058] abutting a second electrode against the separator sheet wherebythe electrodes maintained in a spaced apart configuration;

[0059] containing in a housing the electrodes, the separator sheet andan electrolyte for allowing ionic conduction between the electrodes; and

[0060] connecting two terminals to the respective electrodes forallowing external electrical connection to those electrodes.

[0061] According to a seventh aspect of the invention there is provideda method of forming a supercapacitor, the method including:

[0062] providing a first electrode;

[0063] disposing a second electrode adjacent to the first electrode;

[0064] captively retaining a separator only to the second electrode formaintaining the electrodes in a spaced apart configuration;

[0065] containing in a housing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0066] connecting two terminals to the respective electrodes forallowing external electrical connection to those electrodes.

[0067] According to an eighth aspect of the invention there is provideda method of forming a supercapacitor, the method including:

[0068] providing a first electrode;

[0069] disposing a second electrode adjacent to the first electrode;

[0070] captively retaining a separator to the second electrode and notthe first electrode for maintaining the electrodes in a spaced apartconfiguration;

[0071] containing in a housing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0072] connecting two terminals to the respective electrodes forallowing external electrical connection to those electrodes.

[0073] According to a ninth aspect of the invention there is provided amethod of forming an energy storage device including the steps of:

[0074] providing a first electrode;

[0075] disposing a second electrode adjacent to the first electrode;

[0076] retaining a separator under tension to the second electrode formaintaining the electrodes in a spaced apart configuration;

[0077] containing within a housing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0078] connecting two terminals to the respective electrodes forallowing external electrical connection to those electrodes.

[0079] According to a tenth aspect of the invention there is provided amethod of forming an energy storage device including the steps of:

[0080] providing a first electrode;

[0081] disposing a second electrode adjacent to the first electrode, thesecond electrode having at least one edge;

[0082] providing a separator having two opposed faces that sandwich thesecond electrode and that are abutted and secured together at oradjacent to the edge for maintaining the electrodes in a spaced apartconfiguration;

[0083] retaining a separator under tension to the second electrode formaintaining the electrodes in a spaced apart configuration;

[0084] containing within a housing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0085] connecting two terminals to the respective electrodes forallowing external electrical connection to those electrodes.

[0086] According to an eleventh aspect of the invention there isprovided an electrode pair for a supercapacitor, the electrode pairincluding:

[0087] a first sheet electrode having a conductive energy storageelement with an outer surface and a separator sheet being captivelyretained in abutment with the surface; and

[0088] a second sheet electrode having a conductive energy storageelement with an outer surface that is abutted with the separator sheetwhereby the elements are maintained in a spaced apart configuration.

[0089] According to a twelfth aspect of the invention there is providedan electrode for an energy storage device, the electrode including:

[0090] a conductive energy storage element having an outer surface; and

[0091] a separator being retained in abutment with the surface undertension.

[0092] According to a thirteenth aspect of the invention there isprovided an electrode for an energy storage device, the electrodeincluding:

[0093] a conductive energy storage element having at least one edge; and

[0094] a separator having two opposed faces that sandwich the elementand that are abutted and secured together at the edge.

[0095] Preferably, the separator includes two flexible sheets each ofwhich define one of the opposed faces. More preferably, the sheets areporous. Even more preferably, the opposed faces, in use, are maintainedin tensioned abutment against the second electrode.

[0096] According to a fourteenth aspect of the invention there isprovided an electrode for an energy storage device, the electrode beingformed from a continuous conductive sheet having a first face, a secondface opposite the first face and a plurality of openings extendingbetween the faces, the electrode including:

[0097] a first energy storage element defined by or mounted to some orall of the first face; and

[0098] a separator extending across the first element and at least someof the second face, the separator being attached to itself through theopenings for maintaining the separator adjacent to the sheet.

[0099] Preferably, the electrode of the fourteenth aspect includes asecond energy storage element defined by or mounted to at least part ofthe second face, wherein the separator extends across the secondelement.

[0100] According to a fifteenth aspect of the invention there isprovided an electrode for an energy storage device, the electrode beingformed from a continuous conductive sheet having a first face, a secondface spaced apart from the first face and a plurality of openingsextending between the faces, the electrode including:

[0101] a first energy storage element defined by or mounted to some orall of the first face;

[0102] a second energy storage element defined by or mounted to some orall of the second face; and

[0103] a separator extending across the first and the second elementsand being attached to itself through the openings.

[0104] Preferably, the sheet extends longitudinally and the openings aretransverse slots. More preferably, the slots are longitudinally spacedapart and parallel. Even more preferably, each slot is equallylongitudinally spaced apart from the adjacent slots.

[0105] Preferably also, the sheet includes two transversely spaced apartlongitudinal edges and the slots extend from one edge and terminateadjacent to the other edge. More preferably, the sheet includes twotransversely spaced apart longitudinal edges and the slots extendinwardly from both edges and terminate adjacent to each other.

[0106] In a preferred form, the sheet includes two transversely spacedapart longitudinal edges and the slots terminate adjacent to both edges.

[0107] According to a sixteenth aspect of the invention there isprovided an energy storage device including:

[0108] a plurality of first electrodes that have been separated from acontinuous longitudinally extending sheet, the sheet having a pluralityof longitudinally spaced apart transversely extending slots that extendbetween adjacent ones of the electrodes;

[0109] a plurality of second electrodes that are opposed with at leastone of the first electrodes;

[0110] a separator being disposed between the electrodes for maintainingthe electrodes in a spaced apart configuration;

[0111] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0112] two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.

[0113] According to a seventeenth aspect of the invention there isprovided a method for forming an energy storage device from a continuouslongitudinally extending conductive sheet of a predetermined transversewidth, the method including the steps of:

[0114] forming a plurality of longitudinally spaced apart transverseslots in the sheet, wherein the slots have a transverse extent less thanthe predetermined transverse width to define a plurality of sequentiallylinked first electrode plates;

[0115] engaging a separator with the electrode plates, the plates eachincluding a tab portion that extends transversely beyond the separator;

[0116] separating the electrode plates;

[0117] connecting the tab portions to each other to electrically connectthe electrode plates;

[0118] arranging the first electrode plates with a plurality of secondelectrode plates in a predetermined configuration;

[0119] disposing the electrode plates within a housing containing anelectrolyte for allowing ionic conduction between the plates; and

[0120] connecting two terminals to the respective pluralities ofelectrode plates for allowing external electrical connection to thoseplates.

[0121] Preferably, the sheet includes two opposite transverse edges thatare spaced apart by the predetermined width and the method includes the,step forming the slots such that they extend from one of the transverseedges and terminate adjacent to the other edge.

[0122] More preferably, the step of engaging the separator with theplates includes sandwiching the plates between two opposed separatorsheets. More preferably, the separator sheets are retained in tensionedengagement with the plates.

[0123] In a preferred form, the method includes the further step ofengaging the two opposed separator sheets with each other through theslots. More preferably, the method includes the further step of joiningthe two opposed separator sheets with each other through the slots. Evenmore preferably, the joining of the separator sheets is by way ofbonding.

[0124] In some embodiments the bonding is by way of heat sealing. Inother embodiments the bonding is by way of heat welding. Morepreferably, the heat sealing or welding extends longitudinally acrosssubstantially all the slot. Even more preferably, the heat sealing orwelding extends transversely across substantially all the slot.

[0125] In other embodiments the heat sealing is affected at two or morespaced apart locations in the slot.

[0126] In a preferred form the method includes the step of alternatelystacking the first and the second plurality of plates with each other.More preferably, the method includes the step of stacking the first andthe second plurality of plates with each other in a single stack.

[0127] In a preferred form, the method includes the step of applying acoating to the sheet, wherein the coating includes activated carbonparticles and a binder.

[0128] According to an eighteenth aspect of the invention there isprovided an energy storage device including:

[0129] a plurality of first electrode plates that have been separatedfrom a continuous longitudinally extending conductive sheet;

[0130] a separator engaged with the electrode plates, the plates eachincluding a tab portion that extends transversely beyond the separatorand which are connected to each other to electrically connect theelectrode plates;

[0131] a plurality of second electrode plates being arranged with thefirst electrode plates in a predetermined configuration;

[0132] a housing for containing the electrode plates and an electrolytefor allowing ionic conduction between the plates; and

[0133] two terminals being connected to the respective pluralities oftab portions for allowing external electrical connection to thoseplates.

[0134] According to a nineteenth aspect of the invention there isprovided an energy storage device including:

[0135] a first longitudinally extending sheet electrode;

[0136] a second longitudinally extending sheet electrode being opposedto and transversely displaced with respect to the first electrode todefine an overlap, wherein the electrodes include respective free edgesthat extend transversely outwardly from the overlap and away from eachother;

[0137] a separator being disposed intermediate the electrodes andextending across at least the overlap for maintaining the electrodes ina spaced apart configuration, the separator being folded together withthe electrodes such that the free edges are folded onto themselves todefine respective multi-layer tabs;

[0138] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0139] two terminals connected to the respective tabs for allowingexternal electrical connection to the respective electrodes.

[0140] Preferably, the separator and the electrodes are folded togetherinto a flat spiral. More preferably, the tabs include a plurality oflayers that abut. Even more preferably, the separator and theelectrodes, when folded together, have a first longitudinal extent andthe tabs have a second longitudinal extent which is less than the firstlongitudinal extent.

[0141] Preferably also, respective portions are removed from the freeedges such that the second longitudinal extent is less than one half ofthe first longitudinal extent. More preferably, the second longitudinalextent is less than one third of the first longitudinal extent.

[0142] In a preferred form, the tabs are both adjacent to a longitudinaledge of the device. More preferably, the layers of the tab areelectrically connected.

[0143] Preferably, adjacent layers of the tab are abutted and secured toeach other. More preferably, the securement is by ultrasonic welding.

[0144] According to a twentieth aspect of the invention there isprovided an energy storage device including:

[0145] a first electrode;

[0146] a second electrode being opposed to the first electrode;

[0147] a separator being disposed intermediate the electrodes formaintaining the electrodes in a spaced apart configuration;

[0148] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes;

[0149] a pair of spaced apart openings in the housing; and

[0150] two terminals disposed within the housing and being, at one end,electrically connected to the respective electrodes and, at the otherend, covering the openings and being sealingly engaged with the housingabout the periphery of the openings, whereby the terminals areaccessible through the respective openings to allow external electricalconnection to the electrodes.

[0151] Preferably, the terminals include two opposite planar faces andthe housing includes two opposed sidewalls, whereby one of the sidewallsincludes the pair of openings and each of the sidewalls is sealinglyengaged with one face of each terminal. More preferably, each of thesidewalls has a pair of the spaced openings and wherein those openingsare covered by respective faces of the terminals.

[0152] Preferably also, the sidewalls are peripherally connected. Morepreferably, the sidewalls are integrally connected about at least aportion of their peripheries. Even more preferably, the remainder of theportion of the peripheries are sealingly engaged. In the preferredembodiments the sealing engagement is by heat sealing.

[0153] In a preferred form, the terminals include respective protrusionsthat extends through the respective openings for facilitating externalelectrical connection to the electrodes.

[0154] According to a twenty first aspect of the invention there isprovided an energy storage device including:

[0155] an energy storage element having two electrodes;

[0156] two terminals extending from the element for allowing electricalconnection to the electrodes; and

[0157] a housing for containing the element, the terminals and anelectrolyte for allowing ionic conduction between the electrodes, thehousing being folded.

[0158] Preferably, the housing is folded along a fold line that is at oradjacent to and substantially parallel with and edge of the elementwhereby the element lies on one side of the fold line and a foldedportion lies on the other side of the fold line. More preferably, thehousing is folded along more than one spaced apart fold lines and therespective folded portions overlie the element. Even more preferably,the folded portions do not overlie each other.

[0159] In a preferred form, the folded portions are folded toward eachother. More preferably, the fold line passes through a terminal.

[0160] In some embodiments the device includes two folded portionshaving respective openings that are covered and sealed by respectiveterminals whereby the terminals are electrically accessible via therespective openings. More preferably, the device includes at least onecontact that is secured to one of the terminals through the respectiveopening whereby the contact is sandwiched between the folded portion andthe element.

[0161] According to a twenty second aspect of the invention there isprovided a composite energy storage component including two like devicesof the twenty first aspect wherein the terminals extend from arespective one of the electrode of the devices and the other of theelectrodes of the devices being adjacent to each other and electricallyconnected.

[0162] Preferably, all the folded portions are disposed intermediate theelements to define a folded configuration for the component. Morepreferably, the component includes a mounting member for retaining thecomponent in the folded configuration.

[0163] Preferably also, the other of the electrodes of the devices areelectrically connected via one or more like devices of the seventeenthaspect.

[0164] According to a twenty third aspect of the invention there isprovided an energy storage device including:

[0165] a housing;

[0166] an energy storage element being sealingly contained within thehousing;

[0167] a mount that extends about and captively engages the housing; and

[0168] two terminals that extend from the energy storage element andterminate outside the housing for allowing external electricalconnection to the element.

[0169] Preferably, the mount includes a support frame for receiving thehousing and at least one locking element that extends from the frame forcaptively engaging the housing within the support frame. Preferablyalso, the locking element is integrally formed with the frame and isdeformed into abutment with the housing to captively engage the housingwithin the support frame. Even more preferably, the housing is retainedwithin the frame in a folded configuration.

[0170] According to a twenty fourth aspect of the invention there isprovided an energy storage device including:

[0171] a folded housing;

[0172] at least one energy storage element being sealingly containedwithin the housing;

[0173] a mount that extends about and captively retains the housing inthe folded configuration; and

[0174] two terminals that extend from the energy storage element andterminate outside the housing for allowing external electricalconnection to the element.

[0175] According to a twenty fifth aspect of the invention there isprovided an energy storage device including:

[0176] a plurality of first electrodes having respective first surfacesof a first area;

[0177] a plurality of second electrodes having respective secondsurfaces of a second area, the electrodes being stacked such that thesecond surfaces are opposed to respective first surfaces whereby theopposed surfaces collectively define respective overlapped portionshaving a third area that is less than the first and the second areas;

[0178] a separator having a first edge and a second edge transverselyspaced apart from the first edge, the separator being disposed betweenthe surfaces and extending across at least the overlapped portion formaintaining the electrodes in a spaced apart configuration, wherein thefirst electrodes each include a first tab that extends beyond the firstedge and the second electrodes each include a second tab that extendsbeyond the second edge;

[0179] a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; and

[0180] two terminals being respectively electrically connected to thefirst and the second tabs and being accessible from outside the housingfor allowing external electrical connection to the electrodes.

[0181] Preferably, the first and the second surfaces include respectivecarbon coatings at least in the overlapped portion. More preferably, thefirst and the second electrodes are longitudinally extending sheetelectrodes. Even more preferably, the electrodes are stacked together.In other embodiments, however, the electrodes are wound together about atransverse winding axis.

[0182] Preferably, in the stacked configuration, each electrode issubstantially planar.

[0183] In a preferred form, the first tabs are connected together todefine a first collective tab that is disposed beyond the first edge andthe second tabs are connected together to define a second collective tabthat is disposed beyond the second edge, wherein the first and thesecond collective tabs are electrically connected to respectiveterminals.

[0184] Preferably, the first and the second edges are parallel and thefirst and the second collective tabs extend outwardly and away from eachother.

[0185] Preferably also, the separator includes a plurality of separateporous sheets. More preferably, the sheets are joined at adjacentperipheral edges.

[0186] According to a twenty sixth aspect of the invention there isprovided a mount for an energy storage device, the mount including:

[0187] a frame member having an opening for receiving the device; and

[0188] one or more tabs extending from the frame member for selectivelypreventing progression of the device through the opening,

[0189] Preferably, the tabs are movable between an open configurationand a closed configuration in which the device is respectively allowedand prevented from movement through the opening. More preferably, thetabs are integrally formed with the frame and are deformed into the openand the closed configurations. More preferably, the deformationreversible. In other embodiments, however, the tabs are only deformableonce. That is, the tabs are originally in the open configuration and aredeformed once into the closed configuration once the device is receivedwithin the frame.

[0190] According to a twenty seventh aspect of the invention there isprovided a housing for an energy storage device having at least oneterminal, the housing including:

[0191] a first plastics layer for enclosing the device and which isbonded to the terminal over a contact area;

[0192] a barrier layer exterior to the plastics layer;

[0193] a second plastics layer exterior to the barrier layer;

[0194] an opening through the layers for allowing access to theterminal, wherein the terminal covers the opening and the contact areasurrounds the opening; and

[0195] a filler material intermediate the first plastics layer and theterminal and spread over at least the contact area.

[0196] According to a twenty eighth aspect of the invention there isprovided a terminal for an energy storage device, the terminalincluding:

[0197] a conductive contact surface;

[0198] a first plastics layer for abutting and sealingly engaging thesurface;

[0199] a barrier layer exterior to the plastics layer;

[0200] a second plastics layer exterior to the barrier layer; and

[0201] an opening through the layers for allowing electrical access tothe surface.

[0202] According to a twenty ninth aspect of the invention there isprovided a housing for an energy storage device having at least oneterminal, the housing including:

[0203] a first plastics layer for enclosing the device and which isbonded to the terminal over a contact area;

[0204] a barrier layer exterior to the plastics layer;

[0205] a second plastics layer exterior to the barrier layer;

[0206] an opening through the layers for allowing access to theterminal, wherein the terminal spans the opening; and

[0207] a filler material intermediate the first plastics layer and theterminal and spread over at least the contact area.

[0208] According to a thirtieth aspect of the invention there isprovided an energy storage device including:

[0209] an energy storage cell;

[0210] a housing for containing the cell, the housing having two abuttedportions that are sealed together, wherein the abutted portions are ofsubstantially uniform collective thickness; and

[0211] two terminals connected to the cell for allowing externalelectrical connection with the cell.

[0212] Preferably, the housing includes two openings that are covered bythe respective terminals and two sealing portions that surround and areadjacent to the openings. More preferably, the terminals are planar andthe sealing portions overlie and are sealingly engaged with theterminals. More preferably, that sealing engagement is effected by heat.

[0213] Preferably also, the housing includes a barrier sheet having afirst peripheral edge and a second peripheral edge, wherein the sheet isfolded upon itself so that the peripheral edges define the respectiveabutted portions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0214] Preferred embodiments of the invention will now be described, byway of example only, with reference to the accompanying drawings. Allthe drawings are schematic and none are to scale. Particularly:

[0215]FIG. 1 is a top perspective view of a supercapacitor according tothe invention;

[0216]FIG. 1a is an enlarged front view of an alternative contact forthe supercapacitor of FIG. 1;

[0217]FIG. 2 is an underside view of a supercapacitor of FIG. 1;

[0218]FIG. 2a is a cross sectional view of the supercapacitor of FIG. 2taken along line 2 a-2 a;

[0219]FIG. 3 is a plan view of a carbon coated aluminium sheet that isused to produce an electrode for the supercapacitor of FIG. 1;

[0220]FIG. 4 is a plan view of the sheet of FIG. 3 with a plurality ofslots;

[0221]FIG. 5 is a perspective view of some steps in a manufacturingprocess according to the invention;

[0222]FIG. 6 is a plan view of some additional steps following the stepsof FIG. 5;

[0223]FIG. 7 is a perspective view of some process steps following thesteps of FIG. 6;

[0224]FIG. 8 is a cross section taken along line 8-8 of FIG. 7;

[0225]FIG. 9 is a cross section similar to that of FIG. 8 illustratingan alternative embodiment of the invention;

[0226]FIG. 10 is a cross section similar to that of FIG. 8 illustratinga further embodiment of the invention;

[0227]FIG. 11 is a cross section similar to that of FIG. 8 illustratinga further alternative embodiment of the invention;

[0228]FIG. 11a is a cross section similar to that of FIG. 8 illustratinga further alternative embodiment of the invention;

[0229]FIG. 12 is a perspective view of a rolled combination of sheets;

[0230]FIG. 13 is a perspective view of a cut and stacked combination ofsheets;

[0231]FIG. 14 is a plan view of a capacitive cell with its tabs trimmed;

[0232]FIG. 14a is a plan view of an alternative capacitive cell with itstabs trimmed;

[0233]FIG. 14b is a plan view of a further alternative capacitive cellwith its tabs trimmed;

[0234]FIG. 15 is a plan view of the capacitive cell of FIG. 14 lying onthe sheet that is to be formed into a housing;

[0235]FIG. 15a is an underside view of the housing of FIG. 15;

[0236]FIG. 15b is a view similar to that of FIG. 15, illustrating analternative sheet;

[0237]FIG. 16 is a plan view of a capacitive cell and terminals;

[0238]FIG. 17 is a plan view of the cell of FIG. 14 in a foldedenclosure;

[0239]FIG. 18 is a sectional view taken along line 18-18 of FIG. 17;

[0240]FIG. 19 is a perspective view of two cells being arranged forconnection together;

[0241]FIG. 20 is a perspective view of the cell of FIG. 19 in apartially folded configuration;

[0242]FIG. 21 is a perspective view of the cell of FIG. 20 being furtherfolded;

[0243]FIG. 22 is view similar to that of FIG. 15 of an alternativeembodiment of the invention;

[0244]FIG. 23 is a view similar to that of FIG. 15a for the embodimentof FIG. 22;

[0245]FIG. 24 is a view similar to that of FIG. 17 for the embodiment ofFIG. 22; and

[0246]FIG. 25 is a view similar to that of FIG. 19 for the embodiment ofFIG. 22.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0247] Referring to FIG. 1 there is illustrated a surface mount energystorage device in the form of a supercapacitor 1. The supercapacitorincludes a generally rectangular folded prismatic housing 2 and twoenergy storage elements (not shown) that are sealingly contained withinthe housing and which are connected in series. A mount, in the form ofan integrally formed tinned metal frame 3, extends about and captivelyretains housing 2 in the folded configuration shown. Two terminals, inthe form of elongate contacts 4 and 5 extend from the energy storageelements and terminate outside housing 2 for allowing externalelectrical connection to the elements.

[0248] In this embodiment contacts 4 and 5 are formed into an S-shapeand have planar ends 4 a and 5 a that are soldered or otherwise surfacemounted to a PCB. However, in other embodiments, such as that shown inFIG. 1a, the contacts extend downwardly and through correspondinglocated apertures in the PCB. In this case, the ends, as illustrated bythe end numbered 4 b, are soldered to the side of the PCB that isopposite to supercapacitor 1. In still further embodiments the ends 4 aand 5 a are turned inwardly and toward each other.

[0249] Frame 3 includes two like and parallel elongate planar sidemembers 7 and 8 that are interlinked by two spaced apart transversemembers 9 and 10. Frame 3 also includes four spaced apart feet 11 thatextend outwardly from members 7 and 8 for defining substantially planarcontacts that are abutted and soldered to a PCB. Other forms ofattachments will be understood by those skilled in the art to be equallyapplicable.

[0250] In some embodiments frame 3 is integrally formed from anothermetal such as aluminium. In still further embodiments the frame isconstructed from a plastics material.

[0251] As best shown in FIG. 2, frame 3 also includes four spaced apartand opposed retention tabs 13, 14, 15 and 16 that respectively extendnormally from one of frame members 7 and 8 and toward the other of thosemembers. The tabs are initially parallel with the respective member fromwhich they extend to leave an opening that extends between members 7 and8. The folded housing 2 is inserted through this opening and abuttedagainst members 9 and 10. Thereafter, tabs 13 to 16, which areintegrally connected with respective members 7 and 8, are deformed intothe configuration illustrated in FIGS. 1, 2 and 2 a. This deformation iseffected either manually or, more preferably, by means of automation. Insome embodiments the deformation of the tabs occurs simultaneously,while in other embodiments it occurs sequentially.

[0252] Reference is now made to FIG. 2a which shows a cross sectionalview of supercapacitor 1. More particularly, housing 2 is folded so thatthe two energy storage elements are disposed centrally. Accordingly,housing 2 is thinnest at the regions adjacent to members 9 and 10. It isin these thinner regions that member 9 and 10 extend. Similarly, tabs13, 14, 15 and 16 are deformed into these thinner regions so that thecontribution of frame 3 to the overall thickness of the supercapacitoris minimised. That is, advantage is taken of the non-uniform thicknessof the housing in the folded configuration.

[0253] Frame 3 is punched from a single metal blank that is deformedinto the desired configuration. That is, all members, tabs and feet areintegrally formed. In other embodiments frame 3 is constructed fromother metals and it is also envisaged that other materials such asplastics are suitable. In the latter case it is necessary to glue orotherwise adhere the plastics tabs to the frame. Alternatively, moveableplastics tabs are possible, although at the cost of complexity.

[0254] The construction and packaging of supercapacitor 1 will now bedescribed in more detail. It will be clear from the followingdescription that this embodiment offers considerable scope for variationof the packaging and as such accommodates a wide variety ofapplications. It will also be clear that the construction and packagingof supercapacitor 1 is ideally suited to automation.

[0255] Referring to FIG. 3 there is illustrated in plan view alongitudinally extending aluminium sheet 15 that is used to produce anelectrode for the supercapacitor of FIG. 1. Sheet 15 is continuous andincludes two longitudinally extending edges 16 and 17 that aretransversely spaced apart by 31.5 mm. Sheet 15 also includes a centrallyapplied continuous carbon coating 18 that has two transverse edges 19and 20 that are spaced apart by 15.5 mm. As will be appreciated by thoseskilled in the art, the carbon coating is used to provide a high surfacearea for the electrode. The coating in this embodiment includes:

[0256] carbon particles to provide high surface area and conductivity;and

[0257] a binder to bind the carbon particles to each other and to thesheet.

[0258] Many other coatings or combination of constituents within thecoating are possible. Additionally, for different end applications useis made of different coating thicknesses and different sheet dimensions.

[0259] Sheet 15 is passed to a forming station (not shown) where edge 20is trimmed, as shown in FIG. 4, such that edge 20 defines the peripheryof the sheet. In other embodiments edge 17 is trimmed less and liesclosely adjacent to edge 20.

[0260] As also shown in FIG. 4, edge 16 remains untrimmed so that sheet15 defines a common conductive tab 21 that lies between edges 16 and 19.This tab is about 8 mm wide and its function will be described in moredetail below.

[0261] The same forming station that trims sheet 15 also removesselected portions of the sheet to define a plurality of equallylongitudinally spaced apart transverse slots 22. The slots extendlinearly between respective open ends 23 that are co-terminus with edge20 and closed ends 24 that are intermediate edge 19 and edge 16. Theslots extend at least between edges 19 and 20 to segment coating 18 intoa plurality of like sub-electrodes 25 that extend longitudinally betweenadjacent slots. A skilled addressee will understand from the disclosurewithin this specification that a variety of slot configurations arepossible to achieve this end effect of segmentation. For example, slots22 need not be normal to edges 16, 19 and 20.

[0262] In further embodiments end 24 is co-terminus with edge 19, whilein further embodiments end 24 is closer to edge 16 than is the case forthe embodiment of FIG. 4. Moreover, in some embodiments where edge 17protrudes beyond edge 20 following the rimming step referred to above,end 23 is closed.

[0263] Sub-electrodes 25 have a longitudinal extent of about 12 mm.Moreover, slots 22 are about 2 mm wide. In other embodiments thesub-electrodes and the slots have different dimensions.

[0264] As shown, slots 22 have a transverse extent less than that ofsheet 15. That is, tab 21 is continuous and defines a link betweenadjacent sub-electrodes 25. The advantages of this arrangement are manyfold and will become more apparent from the description below of theother manufacturing steps. However, of particular note is the excellentindexing that the slots provide in those other steps. That is, theregular longitudinal spacing of the slots provides a convenientreference for the speed and extent of travel of sheet 15 through thesubsequent steps. This, in turn, allows a finer control of those stepsand further enhances the suitability of the preferred embodiments tomass manufacturing and automated manufacturing techniques.

[0265] Referring now to FIG. 5, there is illustrated schematically somefurther processing steps. Particularly, two like sheets 15 are arrangedin a back-to-back configuration and feed continuously in the directionof arrows 31 and 32 into a forming station 33. As shown, the carboncoating on both sheets 15 is outwardly facing and each slot coincideswith one slot on the other sheet. That is, each slot directly overlies acorresponding slot in the other sheet.

[0266] In other embodiments the trimming of sheets 15 and the forming ofthe slots 22 does not occur until after those sheets leave station 33.However, as described above, it is preferred that slots 22 are formed atthe earliest possible opportunity to provide a reference for movement ofsheets 15 through the subsequent steps.

[0267] Station 33 includes two counter rotating rollers 34 and 35 thatprogress the two sheets 15 into engagement such that edges 16 areabutted and aligned. In some embodiments the back of one or both of thesheets includes some contact adhesive to facilitate a secure engagementbetween the sheets once they have passed through station 33. However, inthis embodiment that is not required as the sheets are sufficientlyretained together by friction and the tension inherent in themanufacturing process.

[0268] In further embodiments, use is made of a single sheet 15 that hastwo coatings 18, one on each opposite face. In this case, there is noneed to include two sheets 15 in the back-to-back configuration referredto above.

[0269] After sheets 15 leave station 33 they are drawn in the directionof arrow 36 into station 37. Simultaneously with this, two alignedporous separator sheets 39 and 40 are drawn, under tension, in thedirection of respective arrows 41 and 42 and into station 37. Sheets 39and 40 are brought into engagement with the outwardly facing sides ofsheets 15 and extend over all of the exposed coating 18. Sheets 39 and40 are continuous and each have an upper edge 45 and a lower edge 46.These edges are spaced apart by 17.5 mm.

[0270] Station 37 also includes two counter rotating rollers 43 and 44that progress all the sheets into engagement such that edges 46 arealigned and abutted about 1 mm below edge 20. This being the case, tab21 and ends 24 of slots 22 protrude transversely beyond edges 45 ofsheets 39 and 40. In less preferred embodiments sheets 39 and 40 extendtransversely across all of tab 21.

[0271] The sheets 15 are feed into station 33 from electrode feed rolls(not shown) that are maintained at or about a first predeterminedtension. Additionally, sheets 39 and 40 are feed into station 37 fromseparator feed rolls (also not shown) that are maintained at or about asecond predetermined tension which is greater than the first tension.The reason for this will be explained below. It should be noted,however, that in some embodiments the tension applied to all the sheetsis about the same.

[0272] After the abutted sheets leave station 37 they are progressed inthe direction of arrow 50 to a further station 51 shown in FIG. 6.Station 51 is a heat forming station and it applies heat to the sheetsin selected spaced apart areas that overlie or which are adjacent toslots 22. These areas are indicated by reference numerals 52 and 53.Areas 52 are disposed adjacent to edge 45 and end 24 of slots 22. Areas53, however, extend inwardly from edge 46 and overlie ends 23 of slots22.

[0273] The heat applied by station 51 in areas 52 and 53 is sufficientto heat and thermoform sheets 39 and 40. Where these sheets are abuttedthrough the slots, the heat is sufficient to weld the sheets together.That is, sheets 39 and 40 become integrally engaged where areas 52 and53 overlap with the underlying slots 22. Advantageously, that engagementoccurs across the entirety of the longitudinal extent of the slots. Thatis, the sheets are abutted together all the way to the edges ofsub-electrodes 25. However, it has been found that for the presentembodiment it is not necessary to have the sheets 39 and 40 engagedalong all their co-abutting areas.

[0274] Moreover, the heating operation within station 51, and thesubsequent cooling of areas 52 and 53, is conducted while all the sheetsare maintained under tension by the forming machinery. Accordingly, whenthe tension of the machinery is removed sheets 39 and 40 remain capturedto the other layers due to the now integral securement through theslots.

[0275] The affecting of heat welding in areas 53 also adds structuralrigidity to the combination of sheets which allows for a more robusthandling of those sheets during the subsequent process steps.

[0276] The tensional strength of sheets 39 and 40 is relatively highand, further, they exhibit a certain degree of tensional resilience.This, in combination with the tensioned engagement, allows sheets 39 and40 to bear any tensional loads preferentially to the aluminium sheetswhich are easily torn. As, in the configuration shown, sheets 39 and 40create a continuous link between all the sub-electrodes and therebycontribute to the overall structural integrity of the combination ofsheets.

[0277] In other embodiments the areas 52 and 53 are located differently.In one particular further embodiment to areas are joined, in that thethermoformed area extends substantially transversely across sheets 39and 40.

[0278] Areas 52 and 53 are such as to ensure that the thermoforming ofsheets 39 and 40 occurs just beyond the slots and onto the adjacentsub-electrode 25. This ensures that the thermo-engagement between sheets39 and 40 takes place right to the periphery of the slots. That is, toensure that the sheets 39 and 40 remain under tension. The portions ofthe areas 52 and 53 that do not overlie the slots—that is the portionsthat overlie the sub-electrodes—are kept to a minimum.

[0279] Sheets 39 and 40 are thin porous membranes that act as physicaland electrical separators for the coated aluminium sheets that definethe adjacent electrodes in the supercapacitor. A variety of materialsare suitable for use as a separator.

[0280] Each sub-electrode 25 includes a fixed edge defined by edge 19and three free or unbounded edges. Sheets 39 and 40 are engaged witheach other along the three free edges to not only maintain the tensionin the sheets, but also to minimised the risk of relative transversemovement between sheets 15, 39 and 40 during the subsequentmanufacturing steps. In other embodiments, sheets 39 and 40 are engagedagainst only two of the free edges, although preferably the two oppositefree edges.

[0281] Area 52 is substantially rectangular and extends across therespective slot 22 and onto both the adjacent sub-electrodes 22 tooptimise the retention between sheets 15, 39 and 40 and to ensuretension is retained in sheets 39 and 40. In other embodiments, area 52is circular or another shape. In further embodiments, area 52 iscontained wholly within the respective slot 22 and does not extend ontothe adjacent sub-electrodes 22.

[0282] Area 53 is in the form of an inverted T-shape which, like area52, extends across the respective slot 22 and onto both the adjacentsub-electrodes 22. Area 53 is disposed so as the heat engagement that isaffected between sheets 39 and 40 extends up to and abuts the adjacentfree edges of the respective sub-electrodes. That is, the abutment alongthe two adjacent free edges is affected by a heat applied in a singlearea, as opposed to having to provide heat to two separate areas.

[0283] After leaving station 51 the sheets move in the direction ofarrow 55 and, as shown in FIG. 7, into a further station 56.Simultaneously, two continuous carbon coated aluminium sheets 57 and 58are feed into station 56 to overlap with and partially sandwich theother sheets. The sheets 57 and 58 each include upper edges 59 and loweredges 60. Moreover, these sheets include a carbon coating 61 thatextends from edge 57 and which terminates in an edge 62 that is spacedapart from edge 60. The space between edges 60 and 62 defines acontinuous peripheral tab 63. In this embodiment, coating 61 is the sameas coating 18.

[0284] Station 56 includes two counter rotating rollers 65 and 66 thatapply compressive forces to the sheets as well as maintaining the sheetsin tension.

[0285] The sheets are aligned such that, after leaving station 56, edge59 is disposed adjacent to edge 47, although on the opposite side ofedge 47 to edge 16. Additionally, both edges 60 extend transverselybeyond edge 46 and preferably abut. In this configuration, coatings 18are opposed with respective coatings 61. Preferably, the opposedcoatings are directly superimposed. However, some transverse offsetbetween coatings 18 and 61 is tolerable without adversely affecting theperformance of the resultant supercapacitor.

[0286] It will be appreciated from the above description that thecontinuous sheets that merge from station 56 have a cross section asillustrated in FIG. 8. This Figure is not to scale or in proportion butrather schematic so as to more clearly illustrate the relativedisposition of the sheets. Of particular interest is that edges 46 and47 extend beyond the overlap that exists between the back-to-back sheets15. These sheets 15 form a first pair and the opposed sheets 57 and 58form a second pair. Sheets 39 and 40 ensure that the first pair ofsheets are physically and electrically separated from the second pair ofsheets.

[0287] After leaving station 56 the layered combination of sheets arecut transversely along respective cut lines that extend transverselythrough slots 22. While sheets 39, 40, 57 and 58 are cut across theentirety of their respective transverse extents, both sheets 15 are onlycut across tabs 21. Importantly, these tabs do not overlie or overlapwith either of sheets 57 and 58. This allows considerable tolerance toany non-ideal cutting that may take place. That is, if the cuttingprocess is non-ideal and results in deformation of the sheets—as opposedto a clean cut—the chance of an electrical short being created betweensheets 15 and either of sheets 57 and 58 is considerably reduced overknown methods.

[0288] In the case of automated manufacture it is inevitable that theequipment used will operate across a range of tolerances and willprogressively wear. With time, there is an increasing risk of non-idealbehaviour, one of which is the puncturing of one or more of sheets 39and 40. The present embodiment is structured to ensure that the cutsperformed, however non-ideal, are in a region in which there is nooverlap of sheets 57 and 58 with sheets 15. The result is amanufacturing process that is less sensitive to the accuracy of the cutand, as such, one which lends itself to automation and higher yields.

[0289] The cutting of the sheets provides a plurality of electrode unitshaving a cross section the same as that shown in FIG. 8 and a lengthequal to the distance between the centres of adjacent slots 22. Theseplurality of electrode units are stacked back-to-back so that the backof sheet 57 and 58 of one electrode unit are aligned and abutted withthe back of a respective sheet 58 and 57 of another electrode unit. Thenumber of units in the stack is dependent upon the capacitance thatsupercapacitor 1 is designed to provide. The greater the capacitancedesired, the more units that will be required.

[0290] Once the stack is formed, all of tabs 21 are abutted andultrasonically welded together and all of tabs 63 are abutted andultrasonically welded together. An example of a stack is schematicallyillustrated in FIG. 13.

[0291] In an alternative embodiment, the layered combination of sheetsthat leaves station 56 is not cut but, rather, rolled in a flat stackthat has an initial width which is the distance between adjacent slots22. Once rolled, the sheets take the form illustrated in FIG. 12. Thatis, the rolling occurs along a transverse axis and tabs 21 and 63protrude from opposite transverse ends of the roll. The sheets areretained in the rolled configuration by the application of an ultrasonicweld 66 to the roll. While this embodiment is concerned with the rollingof four coated aluminium sheets, in other embodiments more sheets, andthe required separator sheets, are used.

[0292] An alternative approach is to spiral wind the layers and thenflatten them.

[0293] In further embodiments the layered combination of sheets thatleaves station 56 is not cut but, rather, folded in a z-stack with thefolds being made along transverse fold lines that extend through theslots. That is to say, that the sheets are concertinaed. Again, use ismade of an ultrasonic weld or other retention means for retaining thestack in a flattened configuration.

[0294] The above embodiments have only described the use of manyseparate aluminium sheets that are combined. However, in other preferredembodiments use is made of different combinations. For example, FIG. 9is a cross sectional view similar to that of FIG. 8 where correspondingfeatures are denoted by corresponding reference numerals. In thisembodiment, rather than using two back-to-back sheets 15, use is made ofa single folded sheet 15. This folded sheet includes two separate carbonstrips, one each side of the fold. However, in other embodiments, thesheet includes a single carbon strip that is centrally folded uponfolding of the sheet as a whole.

[0295] Another example is provided in FIG. 10 where sheet 15 includes acarbon coating on both sides and, as such, only a single thickness ofsheet 15 is required. A further example is shown in FIG. 11 where sheets57 and 58 are integrally formed and folded about a common fold line 65.

[0296] A further example is illustrated in FIG. 11a where use is made oftwo folded electrodes.

[0297] Other combinations are possible as would be now understood fromthe teaching herein.

[0298] In all these embodiments, however, tabs 21 extend transverselyfrom edges 47 of sheets 39 and 40, while tabs 63 extend transverselyfrom edges 46 of sheets 39 and 40 in the opposite direction to tabs 21.The combination of sheets 15 form a first electrode of a firstcapacitive cell of the supercapacitor while the combination of sheets 57and 58 form a second electrode of the first capacitive cell of thesupercapacitor. Accordingly, it is important that good electricalcontact is established between separate sheets 15 and good electricalcontact is established between sheets 57 and 58. Conversely, it isimportant to ensure a high electrical resistance exists between sheets15 and both of sheets 57 and 58. The first consideration is accommodatedby the interconnection of like tabs which are overlapped at oppositetransverse ends of the cell. The second consideration is accommodated bysheets 39 and 40 that extend across and beyond all the overlapping areasbetween sheets 15 and sheets 57 and 58.

[0299] The next stage in the manufacturing process is to trim the tabs21 and 63. More particularly, reference is made to FIG. 14 where acapacitive cell 70 is illustrated. This cell has had the tabs tried toabout half their initial longitudinal extent. In other embodiments thetrimming removes a different amount of the tabs. For example, in theembodiment illustrated in FIG. 14a one end of each tab is trimmed at anacute angle. This is done to better improve the packing density of theoverall supercapacitor. That is, such a supercapacitor uses a number ofthe cells in a folded configuration and, depending upon the nature ofthe folding used, there is advantage to be gained by judicious trimmingat this stage in the process. This effect will be discussed furtherbelow.

[0300] In another example illustrated in FIG. 14b, the tabs are trimmedsymmetrically about the centre line of the cell. More particularly, oneend of both tabs are trimmed at an acute angle, while the other end ofboth tabs is trimmed at an obtuse angle.

[0301] While it is usual to have the tabs equally trimmed, in someembodiments this does not occur. Additionally, in this embodiment thetabs are trimmed from the centre to one end. However, in alternativeembodiments, the remaining tab is central, not offset.

[0302] Tabs 21 and 63 are then attached to respective substantiallyplanar rectangular terminals 67 and 68, as shown in FIG. 16. Theterminals are made from aluminium and extend transversely outwardly fromthe respective tabs and away from each other. The attachment in thisembodiment is by way of ultrasonic welding, although in otherembodiments use is made of conductive adhesives, soldering, or otherlike means.

[0303] Terminals 67 and 68 have dimensions of about 10×8×0.15 mm. Inother embodiments different thickness are used depending upon thecurrent carrying capacity for which the supercapacitor is designed. Forthe more usual supercapacitors, the thickness of the terminals is in therange of about 100 microns to about 300 microns.

[0304] As best shown in FIG. 15, cell 70, which is illustrated inghosted outline, is intended to be placed on a flexible laminate sheet71. The sheet is symmetrical about fold line 72 and includes four spacedapart circular openings 73, 74, 75 and 76 that extend through the sheet.For convenience, the portions of sheet 71 that lie above and below line72 will be referred to as portion 77 and portion 78 respectively.

[0305] Based upon the teaching herein it will be appreciated by thoseskilled in the art that sheet 71 need not be the shape shown in FIG. 15.For example, two alternative sheets 71 are illustrated in FIGS. 15a and15 b respectively.

[0306] In the FIG. 15 embodiment, openings 73, 74,75 and 76 are 4 mm indiameter. In other embodiments alternative diameters are used. Infurther embodiments the openings are other than circular. For example,some embodiments make use of generally square openings, in that theopenings include four straight sides that are joined by rounded corners.

[0307] As will become clear from the following description, theterminals are to be sealingly engaged with sheet 71 at least about theperiphery of openings 73, 74, 75 and 76. Accordingly, in someembodiments, both side of terminals 67 and 68 are coated with anadhesive or sealant to facilitate the required engagement. However, inother embodiments neither of these additional substances is required dueto the properties of sheet 71.

[0308] Sheet 71 includes an internal aluminium layer to provide highbarrier properties to the ingress and egress of fluids through andsheet. Moreover, the sheet includes at least one outer layer that isthermoformable into sealing engagement with itself and terminals 67 and68. An example of a preferred sheet 71 is disclosed in Australianprovisional patent application no. PQ8700 filed on Jul. 10, 2000, thedisclosure of which is incorporated herein by way of cross reference.However, other laminate sheets are also suitable.

[0309] Cell 70 is placed on sheet 71 such that it lies only on portion77 and with terminals 67 and 68 covering completely respective openings73 and 75. Portion 78 is then folded along line 72 back over cell 70 andportion 77. The resultant configuration is illustrated in FIG. 17. Thisfigure also includes cross-hatching to indicate the three areas 81, 82and 83 of the folded sheet 71 to which pressure and heat aresubsequently applied to seal cell 70 within sheet 71.

[0310] The heat applied to area 81 is sufficient in intensity andduration to cause the portions 77 and 78 to be thermoformed into sealingengagement with each other along all of their abutting peripheries. Asterminals 67 and 68 do not extend outwardly from between the abuttedperipheries of portions 77 and 78, those abutted peripheries lying inarea 81 provide, in combination, a laminate of substantially uniformthickness. This facilitates the application of the heat and pressure toarea 81 and improves the sealing between portions 7 and 78. That is, theuniform thickness reduces the risk of uneven thermal loading across area81 and, hence, allows more precise control of the heating and sealingprocess. This, in turn, further enhances the applicability of thepresent manufacturing method to automation.

[0311] Preferably, cell 70 is wetted thoroughly with electrolyte priorto placement on sheet 71. In other embodiments, however, the heatsealing is a two step operation and the electrolyte is deposited intothe housing formed by sheet 71 between those two steps.

[0312] It will be understood by the skilled address that the electrolyteallows for ionic conduction between the electrodes in the cell and thata variety of electrolytes are available.

[0313] The heat that is applied to sheet 71 is also sufficient to affectsealing engagement between sheet 71 and terminals 67 and 68 in areas 82and 83. While not shown, it will be appreciated that portion 77 of sheet71 is also thermoformed into sealing engagement with the adjacentsurfaces of terminals 67 and 68. That is, areas 82 and 83 are replicatedon the rear of the terminals.

[0314] As the planar area of terminals 67 and 68 is large in relative tothe area of openings 73, 74, 75 and 76 there is considerable tolerancewithin the process to misalignment of cell 70 on sheet 71.

[0315] Area 82 and 83 provide respective substantially planar sites ofuniform thickness. Accordingly, as with the uniformly thick area 81,similar advantages apply to the heating and sealing operation.

[0316] In this embodiment, and as shown in FIG. 18, sheet 71 includes anouter layer 85 of PET, an intermediate aluminium layer 86 and an innerlayer 87 of polyethylene. Upon the application of heat to areas 82 and83, layer 87 softens preferentially to the other layers and bonds to theadjacent terminal. It is emphasised that this Figure, like the others,is not to scale and that the proportions have been exaggerated to moreclearly illustrate the features of the preferred embodiment.

[0317] The heat sealing of sheet 71 to the terminals will be describedwith reference to FIG. 18. That is, two opposed heated plates (notshown) are progressed into engagement with the opposite areas 82. Theplates apply both heat and compressive force to the material that issandwiched between the plates. The heat softens layers 85 and 87, withthe latter being more affected due to its lower melting point. Thissoftening, in combination with the compressive force, results in sheet71 being flattened in area 82.

[0318] After the heat source is removed from all areas, and theresultant structure allowed to cool, sheet 71 provides a sealed housing88 for cell 70 and the electrolyte. It is important to note, however,that both planar sides of both terminals 67 and 68 are accessible due toopenings 73, 74, 75 and 76.

[0319] As illustrated in FIG. 19, two like cells 70 are contained withinrespective housings 88 and are stacked together and attached to eachother. That is, terminal 67 of one cell is ultrasonically welded toterminal 67 of the other of the cells. This welding is possible asaccess to both sides of the terminals is provided. That is, one contactof the welder is engaged with the outer face of terminal 67 of one ofthe cells, while the other contact of the welder is engaged with theouter face of the terminal 67 of the other of the cells. The contactsare then biased toward each other to abut the opposed faces of theterminals 67. The welder is then actuated to weld the abutted terminalstogether.

[0320] The two free terminals 68 provide a site for attachment ofrespective aluminium contact 89 and 90. Both contacts are ultrasonicallywelded to the respective terminals. Again, this operation is possible asaccess to both sides of the terminal is provided. As shown in FIG. 19,the contacts are attached opposite to each other in that they are on theoutermost surfaces of the terminals. Additionally, the contacts extendaway from the terminals and each other to minimise any risk ofinadvertent electrical contact with each other.

[0321] Once the welding has been completed, housings 88 are connected toform a package 92, as best shown in FIG. 20. This package is foldedinitially about parallel spaced apart fold lines 93, 94 and 95, thefirst two of which are also shown in FIG. 17. The fold lines all passthrough tabs 21 or 63, but do not pass through the thicker terminals 67and 68. In other embodiments, however, the fold does pass throughterminals 67 and 68.

[0322] As shown in FIG. 21, the folding is such that the terminals 67and 68 are folded back onto the cell. Moreover, in this embodiment theportions that are folded back across the cell do not overlap with eachother and therefore keep the thickness of the package as a whole to aminimum.

[0323] In other embodiments, area 81 of sheet 71 is greater to provide agreater minimum seal path for the device. This is required for somecombinations of:

[0324] 1. Performance specification—such as raised operationaltemperatures;

[0325] 2. Type of sheet 71; and

[0326] 3.Type of electrolyte.

[0327] In such embodiments there is some overlap between the portionsthat are folded back over the cell. However, there is no overlap ofterminals 67 and 68.

[0328] Package 92 is also folded along fold lines 96. The foldedportions overlap with the cell and are folded onto the same side of thecell as the other folded portions. In this embodiment all the foldedportions do not overlap each other, although in other embodiments thisdoes occur.

[0329] It will be appreciated that it is not critical if the fold alonglines 96 causes some overlap, as this portion is relatively thin, beingonly two layers of sheet 71. The thickest folded components areterminals 67 and 68 and, as such, from a packing density point of view,these are the more important determinants of the overall thickness ofthe supercapacitor.

[0330] Reference is now made to FIG. 21 which shows package 92 as it isfurther folded. As illustrated, all the folded portions are foldedinwardly and across the cell to provide smooth continuous outer faces98. That is, all the folded portions are contained and captured betweenthe separate housings 88 and are not exposed. Accordingly, the risk ofthe folded portions returning to their original unfolded configurationsis minimised. It also provides a substantially clean and planar exteriorsurface to minimise the risk of the housing catching or fouling withother objects inadvertently during the automated manufacturing process.

[0331] In this folded configuration contacts 89 and 90 extend outwardlyfrom package 92. These are subsequently deformed to extend back alongtheir respective lengths and toward each other. An additionaldeformation is then applied such that the contacts extend outwardly frombetween the folded housing 88, as best shown in FIG. 1.

[0332] A skilled addressee will note from FIG. 21 that the two terminals68 have exposed faces that are closely adjacent in the folded package.In some embodiments these exposed faces are coated with an electricallyinsulating material to prevent any inadvertent contact of the terminals.An example of such a material is an epoxy resin.

[0333] All the heat welds that are performed to package 92 are to planarsurfaces. That is, areas 81, 82 and 83 are substantially planar acrosstheir entirety. Accordingly, the heat seal is not compromised by contourvariations as is suffered by prior art products. Moreover, the area ofthe seal is large and therefore less sensitive to manufacturingtolerances.

[0334] The embodiment described above and as illustrated in thedrawings, the two like cells 88 are connected in series. In otherembodiments supercapacitor 1 include more than two cells in series. Infurther embodiments cells 88 are connected in parallel. Moreover, someembodiments include a hybrid series/parallel combination.

[0335] Package 92, in the folded configuration, is received within frame3 and captively retained in that configuration. In the presentembodiment, tabs 13, 14, 15 and 16 of frame 3 are movable between anopen configuration and a closed configuration (as shown in FIG. 1) inwhich the package is respectively allowed and prevented from movementthrough the opening. The tabs are integrally formed with the frame andare deformed into the open and the closed configurations. As frame 3 isformed from tinned metal, the deformation of tabs 13, 14, 15 and 16 isreversible. In other embodiments, however, the tabs are only deformableonce. That is, the tabs are originally in the open configuration and aredeformed once only into the closed configuration when package 92 isreceived within the frame.

[0336] As tabs 13, 14, 15 and 16 are deformed into engagement with thethinner portion of the folded cells, it does not unnecessarilycontribute to the overall dimensions of the supercapacitor.

[0337] Frame 3 not only applies a compressive force to housing 2 toretain it in the folded configuration, but also takes the mechanicalload from contacts 4 and 5.

[0338] Reference is now made to the embodiment of the inventionillustrated in FIGS. 22 to 25 where corresponding features are denotedby corresponding reference numbers. For the sake of clarity, not allreference numerals have been reproduced.

[0339] As best shown in FIG. 23, openings 73, 74, 75 and 76, while beingsymmetrically disposed about fold line 72, are generally square asopposed to the round openings of the other embodiment. Additionally,tabs 67 and 68 extend across the openings but, unlike the correspondingtabs in the earlier embodiment, they do not completely cover thoseopenings.

[0340] This configuration allows the heating and sealing operation tooccur across a large continuous area 81, as shown in FIG. 24. That is,only a single area has heat and pressure applied to it, as opposed tothe three separate areas 81, 82 and 83 of the FIG. 17 embodiment.

[0341] Additionally, once the heating and sealing has been affected, thehousing 88 of FIG. 24 is cut along a trim line 99 that is shown in theFigure as a broken line. Two of the housings 88 are shown in FIG. 25.

[0342] The initial heating and sealing across a continuous region, andlater trmming, provides the following advantages:

[0343] 1. The greater area of sheet 71 makes it easier to handle andmanoeuvre during the heating and sealing operation;

[0344] 2. The cutting allows a greater amount of sheet 71 to be removed,hence increasing the packing density of the resultant device;

[0345] 3. The trim line 99 does not pass through any region where sheet71 overlies terminals 67 and 68. One contributing factor to this is thatthe terminals do not cover the respective openings. Accordingly, therisk of shorting those terminals to the aluminium layer 86 during thecutting operation is minimised if not avoided.

[0346] 4. As the cutting occurs after the sealing, the manufacturing isless sensitive to the initial positioning of cell 70 on sheet 71, thelength of terminals 67 and 68, and the positioning of terminals 67 and68 following their attachment to respective tabs 21 and 63.

[0347] Once the cutting only trim line 99 has occurred, as shown in FIG.25, terminals 67 and 68 are exposed and easily accessible for attachmentto another terminal, or to contacts 89 and 90, as the case may be. Thetwo cells 88 of FIG. 25 are attached and folded similarly to theembodiment shown in FIGS. 19 to 21. The folded structure is then placedwithin a frame to maintain that folded configuration and to facilitatemounting of the resultant supercapacitor.

[0348] The process of producing the supercapacitor of the preferredembodiments described above is extremely well suited to mass productionand repeatability of manufacture. This is because the process:

[0349] 1. Allows use of continuous feeds of sheet material;

[0350] 2. Is robust because the slots:

[0351] a) Prevent undesired short circuits between the electrodes due tothe cutting operation; and

[0352] b) Allow indexing of the continuous materials. This, in turn,allows an accurate progression of these materials as the rollers andother tensioning equipment is able to be automatically calibrated;

[0353] 3. Allows great variation in the parameters of the end product.That is, there is little complication involved in using more or lesscoated aluminium layers or layers of different thickness or composition;

[0354] 4. All the heat welds are performed on planar surfaces whicheliminates the variations and cavities from which prior art heat weldingsuffers.

[0355] 5. All the heat welds are large in area to minimise the risk ofleakage or subsequent contamination.

[0356] 6. Provides relatively large planar terminals and small openingsin the housing. As such, the electrical resistance of the terminal islow without the need to compromise the heat seal. The primary factor forselection of the terminal thickness is the desired overall thickness ofthe packaging, not the effectiveness of the seal.

[0357] 7. Allows a wide tolerance of heat sealing temperatures whenusing the preferred housing material.

[0358] 8. Ensures that the electrode tabs extend outwardly and away fromeach other which substantially reduces the risk of contact between thetabs.

[0359] This increased robustness of the preferred embodiment provides asupercapacitor that is extremely cost effective to produce as it allowsthe use of automated manufacturing techniques to a level beyond knownprocesses. Moreover, it allows the use of soft packaging that is moreversatile both in manufacture and use. Also, it provides long seal pathsthat ameliorate leakage issues that plague the prior art devices.

[0360] Although the invention has been described with reference tospecific examples it will be appreciated by those skilled in the artthat it may be embodied in many other forms.

1. A supercapacitor including: a first electrode; a separator sheet thatis captively retained to the first electrode; a second electrode beingabutted against the separator sheet whereby the electrodes aremaintained in a spaced apart configuration; a housing for containing theelectrodes, the separator sheet and an electrolyte for allowing ionicconduction between the electrodes; and two terminals connected to therespective electrodes for allowing external electrical connection tothose electrodes.
 2. A supercapacitor including: a first electrode; asecond electrode disposed adjacent to the first electrode; a separatorbeing captively retained only to the second electrode for maintainingthe electrodes in a spaced apart configuration; a housing for containingthe electrodes, the separator and an electrolyte for allowing ionicconduction between the electrodes; and two terminals connected to therespective electrodes for allowing external electrical connection tothose electrodes.
 3. A supercapacitor including: a first electrode; asecond electrode disposed adjacent to the first electrode; a separatorbeing captively retained to the second electrode and not the firstelectrode for maintaining the electrodes in a spaced apartconfiguration; a housing for containing the electrodes, the separatorand an electrolyte for allowing ionic conduction between the electrodes;and two terminals connected to the respective electrodes for allowingexternal electrical connection to those electrodes.
 4. An energy storagedevice including: a first electrode; a second electrode disposedadjacent to the first electrode; a separator being retained to thesecond electrode under tension for maintaining the electrodes in aspaced apart configuration; a housing for containing the electrodes, theseparator and an electrolyte for allowing ionic conduction between theelectrodes; and two terminals connected to the respective electrodes forallowing external electrical connection to those electrodes.
 5. Anenergy storage device including: a first electrode; a second electrodedisposed adjacent to the first electrode, the second electrode having atleast one edge; a separator having two opposed faces that sandwich thesecond electrode and which are abutted and joined together at the edgefor maintaining the electrodes in a spaced apart configuration; ahousing for containing the electrodes, the separator and an electrolytefor allowing ionic conduction between the electrodes; and two terminalsconnected to the respective electrodes for allowing external electricalconnection to those electrodes.
 6. An energy storage device according toclaim 5 wherein the second electrode includes at least three edges andthe opposed faces are abutted and joined together at all those edges. 7.An energy storage device according to claim 5 or claim 6 wherein theopposed faces are abutted and joined together along less than theentirety of each edge.
 8. An energy storage device according to claim 5wherein the separator includes two porous sheets that are peripherallyconnected to each other.
 9. An energy storage device according to claim5 wherein the second electrode is a sheet electrode having a first side,a second side that is opposed to the first side, and a common peripheraledge joining the first side and the second side, and the separatorincludes: a first porous sheet that extends across the first side andwhich includes at least one first edge that protrudes beyond the commonperipheral edge; and a second porous sheet that extends across thesecond side and which includes at least one second edge that protrudesbeyond the common peripheral edge wherein the first and second edges areconnected for captively retaining the separator to the second electrode.10. An energy storage device according to claim 9 wherein the connectionof the first and the second edges involves bonding the first and secondedges together.
 11. An energy storage device according to claim 10wherein the bonding includes heat welding those edges together.
 12. Anenergy storage device according to claim 10 wherein the bonding includesadhering those edges together.
 13. An energy storage device according toclaim 10 wherein the bonding includes heat sealing the edges together.14. An energy storage device according to claim 5 including: a likeplurality of first and second electrodes that are alternated with eachother and contained within the housing, all the first electrodes beingelectrically connected to one of the terminals and all the secondelectrodes being connected to the other terminal; and a plurality oflike separators each extending about a respective second electrode tomaintain that electrode in a spaced apart configuration from the or eachadjacent first electrode.
 15. An energy storage device according toclaim 14 wherein the second electrode is formed from a continuouslongitudinally extending conductive sheet having a plurality of spacedapart transverse slots and the porous sheets are connected to each otherthrough the slots.
 16. An energy storage device according to claim 15wherein the conductive sheet is cut transversely through the slots toprovide a plurality of separate sub-electrodes.
 17. An energy storagedevice according to claim 16 wherein the slots are equallylongitudinally spaced apart and the sub-electrodes are substantiallyequivalent.
 18. An energy storage device according to claim 16 whereinthe first electrode includes a plurality of separate sub-electrodes thatare stacked together alternately with a corresponding plurality ofsub-electrodes of the second electrode.
 19. An energy storage deviceaccording to claim 18 wherein each sub-electrode includes an electrodearea and the sub-electrodes of the first and the second electrodesinclude respective first and second tabs extending outwardly from thecorresponding electrode areas.
 20. An energy storage device according toclaim 19 wherein the sub-electrodes are stacked such that the electrodeareas of all the electrodes overlap and the first tabs overlap eachother and are electrically connected and the second tabs overlap eachother and are electrically connected, whereby the first tabs and thesecond tabs do not overlap each other.
 21. An energy storage deviceaccording to claim 5 wherein the separator includes two flexible sheetseach of which define one of the opposed faces.
 22. An energy storagedevice according to claim 21 wherein the flexible sheets are porous. 23.An energy storage device according to claim 21 wherein the opposedfaces, in use, are maintained in tensioned abutment against the secondelectrode.
 24. A method of forming a supercapacitor, the methodincluding: providing a first electrode; captively retaining a separatorsheet to the first electrode; abutting a second electrode against theseparator sheet whereby the electrodes are maintained in a spaced apartconfiguration; containing in a housing the electrodes, the separatorsheet and an electrolyte for allowing ionic conduction between theelectrodes; and connecting two terminals to the respective electrodesfor allowing external electrical connection to those electrodes.
 25. Amethod of forming a supercapacitor, the method including: providing afirst electrode; disposing a second electrode adjacent to the firstelectrode; captively retaining a separator only to the second electrodefor maintaining the electrodes in a spaced apart configuration;containing in a housing the electrodes, the separator and an electrolytefor allowing ionic conduction between the electrodes; and connecting twoterminals to the respective electrodes for allowing external electricalconnection to those electrodes.
 26. A method of forming asupercapacitor, the method including: providing a first electrode;disposing a second electrode adjacent to the first electrode; captivelyretaining a separator to the second electrode and not the firstelectrode for maintaining the electrodes in a spaced apartconfiguration; containing in a housing the electrodes, the separator andan electrolyte for allowing ionic conduction between the electrodes; andconnecting two terminals to the respective electrodes for allowingexternal electrical connection to those electrodes.
 27. A method offorming an energy storage device including the steps of: providing afirst electrode; disposing a second electrode adjacent to the firstelectrode; retaining a separator under tension to the second electrodefor maintaining the electrodes in a spaced apart configuration;containing within a housing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; andconnecting two terminals to the respective electrodes for allowingexternal electrical connection to those electrodes.
 28. A method offorming an energy storage device including the steps of: providing afirst electrode; disposing a second electrode adjacent to the firstelectrode, the second electrode having at least one edge; providing aseparator having two opposed faces that sandwich the second electrodeand that are abutted and secured together at or adjacent to the edge formaintaining the electrodes in a spaced apart configuration; retaining aseparator under tension to the second electrode for maintaining theelectrodes in a spaced apart configuration; containing within a housingthe electrodes, the separator and an electrolyte for allowing ionicconduction between the electrodes; and connecting two terminals to therespective electrodes for allowing external electrical connection tothose electrodes.
 29. An electrode pair for a supercapacitor, theelectrode pair including: a first sheet electrode having a conductiveenergy storage element with an outer surface and a separator sheet beingcaptively retained in abutment with the surface; and a second sheetelectrode having a conductive energy storage element with an outersurface that is abutted with the separator sheet whereby the elementsare maintained in a spaced apart configuration.
 30. An electrode for anenergy storage device, the electrode including: a conductive energystorage element having an outer surface; and a separator being retainedin abutment with the surface under tension.
 31. An electrode for anenergy storage device, the electrode including: a conductive energystorage element having at least one edge; and a separator having twoopposed faces that sandwich the element and that are abutted and securedtogether at the edge.
 32. An electrode according to claim 31 wherein theseparator includes two flexible sheets each of which define one of theopposed faces.
 33. An electrode according to claim 32 wherein the sheetsare porous.
 34. An electrode according to claim 31 wherein the opposedfaces, in use, are maintained in tensioned abutment against the secondelectrode.
 35. An electrode for an energy storage device, the electrodebeing formed from a continuous conductive sheet having a first face, asecond face opposite the first face and a plurality of openingsextending between the faces, the electrode including: a first energystorage element defined by or mounted to some or all of the first face;and a separator extending across the first element and at least some ofthe second face, the separator being attached to itself through theopenings for maintaining the separator adjacent to the sheet.
 36. Anelectrode according to claim 35 including a second energy storageelement defined by or mounted to at least part of the second face,wherein the separator extends across the second element.
 37. Anelectrode for an energy storage device, the electrode being formed froma continuous conductive sheet having a first face, a second face spacedapart from the first face and a plurality of openings extending betweenthe faces, the electrode including: a first energy storage elementdefined by or mounted to some or all of the first face; a second energystorage element defined by or mounted to some or all of the second face;and a separator extending across the first and the second elements andbeing attached to itself through the openings.
 38. An electrodeaccording to claim 37 wherein the sheet extends longitudinally and theopenings are transverse slots.
 39. An electrode according to claim 37wherein the slots are longitudinally spaced apart and parallel.
 40. Anelectrode according to claim 39 wherein each slot is equallylongitudinally spaced apart from the adjacent slots.
 41. An electrodeaccording to claim 37 wherein the sheet includes two transversely spacedapart longitudinal edges and the slots extend from one edge andterminate adjacent to the other edge.
 42. An electrode according toclaim 37 wherein the sheet includes two transversely spaced apartlongitudinal edges and the slots extend inwardly from both edges andterminate adjacent to each other.
 43. An electrode according to claim 37wherein the sheet includes two transversely spaced apart longitudinaledges and the slots terminate adjacent to both edges.
 44. An energystorage device including: a plurality of first electrodes that have beenseparated from a continuous longitudinally extending sheet, the sheethaving a plurality of longitudinally spaced apart transversely extendingslots that extend between adjacent ones of the electrodes; a pluralityof second electrodes that are opposed with at least one of the firstelectrodes; a separator being disposed between the electrodes formaintaining the electrodes in a spaced apart configuration; a housingfor containing the electrodes, the separator and an electrolyte forallowing ionic conduction between the electrodes; and two terminalsconnected to the respective electrodes for allowing external electricalconnection to those electrodes.
 45. A method for forming an energystorage device from a continuous longitudinally extending conductivesheet of a predetermined transverse width, the method including: forminga plurality of longitudinally spaced apart transverse slots in thesheet, wherein the slots have a transverse extent less than thepredetermined transverse width to define a plurality of sequentiallylinked first electrode plates; engaging a separator with the electrodeplates, the plates each including a tab portion that extendstransversely beyond the separator; separating the electrode plates;connecting the tab portions to each other to electrically connect theelectrode plates; arranging the first electrode plates with a pluralityof second electrode plates in a predetermined configuration; disposingthe electrode plates within a housing containing an electrolyte forallowing ionic conduction between the plates; and connecting twoterminals to the respective pluralities of electrode plates for allowingexternal electrical connection to those plates.
 46. A method accordingto claim 45 wherein the sheet includes two opposite transverse edgesthat are spaced apart by the predetermined width and the method includesforming the slots such that they extend from one of the transverse edgesand terminate adjacent to the other edge.
 47. A method according toclaim 45 wherein the step of engaging the separator with the platesincludes sandwiching the plates between two opposed separator sheets.48. A method according to claim 47 wherein the separator sheets areretained in tensioned engagement with the plates.
 49. A method accordingto claim 47 including the further step of engaging the two opposedseparator sheets with each other through the slots.
 50. A methodaccording to claim 49 including the further step of joining the twoopposed separator sheets with each other through the slots.
 51. A methodaccording to claim 50 wherein the joining of the separator sheets is byway of bonding.
 52. A method according to claim 51 wherein the bondingis by way of heat sealing.
 53. A method according to claim 51 whereinthe bonding is by way of heat welding.
 54. A method according to claim52 or claim 53 wherein the heat sealing or welding extendslongitudinally across substantially all the slot.
 55. A method accordingto claim 52 or claim 53 wherein the heat sealing or welding extendstransversely across substantially all the slot.
 56. A method accordingto claim 52 or claim 53 wherein the heat sealing is affected at two ormore spaced apart locations in the slot.
 57. A method according to claim45 including alternately stacking the first and the second plurality ofplates with each other.
 58. A method according to claim 57 including thestep of stacking the first and the second plurality of plates with eachother in a single stack.
 59. A method according to claim 45 includingthe step of applying a coating to the sheet, wherein the coatingincludes activated carbon particles and a binder.
 60. An energy storagedevice including: a plurality of first electrode plates that have beenseparated from a continuous longitudinally extending conductive sheet; aseparator engaged with the electrode plates, the plates each including atab portion that extends transversely beyond the separator and which areconnected to each other to electrically connect the electrode plates; aplurality of second electrode plates being arranged with the firstelectrode plates in a predetermined configuration; a housing forcontaining the electrode plates and an electrolyte for allowing ionicconduction between the plates; and two terminals being connected to therespective pluralities of tab portions for allowing external electricalconnection to those plates.
 61. An energy storage device including: afirst longitudinally extending sheet electrode; a second longitudinallyextending sheet electrode being opposed to and transversely displacedwith respect to the first electrode to define an overlap, wherein theelectrodes include respective free edges that extend transverselyoutwardly from the overlap and away from each other; a separator beingdisposed intermediate the electrodes and extending across at least theoverlap for maintaining the electrodes in a spaced apart configuration,the separator being folded together with the electrodes such that thefree edges are folded onto themselves to define respective multi-layertabs; a housing for containing the electrodes, the separator and anelectrolyte for allowing ionic conduction between the electrodes; andtwo terminals connected to the respective tabs for allowing externalelectrical connection to the respective electrodes.
 62. A deviceaccording to claim 61 wherein the separator and the electrodes arefolded together into a flat spiral.
 63. A device according to claim 61wherein the tabs include a plurality of layers that abut.
 64. A deviceaccording to claim 61 wherein the separator and the electrodes, whenfolded together, have a first longitudinal extent and the tabs have asecond longitudinal extent which is less than the first longitudinalextent.
 65. A device according to claim 64 wherein respective portionsare removed from the free edges such that the second longitudinal extentis less than one half of the first longitudinal extent.
 66. A deviceaccording to claim 64 wherein the second longitudinal extent is lessthan one third of the first longitudinal extent.
 67. A device accordingto claim 61 wherein the tabs are both adjacent to a longitudinal edge ofthe device.
 68. A device according to claim 61 wherein the layers of thetab are electrically connected.
 69. A device according to claim 61wherein adjacent layers of the tab are abutted and secured to eachother.
 70. A device according to claim 69 wherein the securement is byultrasonic welding.
 71. An energy storage device including: a firstelectrode; a second electrode being opposed to the first electrode; aseparator being disposed intermediate the electrodes for maintaining theelectrodes in a spaced apart configuration; a housing for containing theelectrodes, the separator and an electrolyte for allowing ionicconduction between the electrodes; a pair of spaced apart openings inthe housing; and two terminals disposed within the housing and being, atone end, electrically connected to the respective electrodes and, at theother end, covering the openings and being sealingly engaged with thehousing about the periphery of the openings, whereby the terminals areaccessible through the respective openings to allow external electricalconnection to the electrodes.
 72. A device according to claim 71 whereinthe terminals include two opposite planar faces and the housing includestwo opposed sidewalls, whereby one of the sidewalls includes the pair ofopenings and each of the sidewalls is sealingly engaged with one face ofeach terminal.
 73. A device according to claim 71 wherein each of thesidewalls has a pair of the spaced openings and wherein those openingsare covered by respective faces of the terminals.
 74. A device accordingto claim 71 wherein the sidewalls are peripherally connected.
 75. Adevice according to claim 74 wherein the sidewalls are integrallyconnected about at least a portion of their peripheries.
 76. A deviceaccording to claim 75 wherein the remainder of the portion of theperipheries are sealingly engaged.
 77. A device according to claim 71wherein the sealing engagement is by heat sealing.
 78. A deviceaccording to claim 71 wherein the terminals include respectiveprotrusions that extend through the respective openings for facilitatingexternal electrical connection to the electrodes.
 79. An energy storagedevice including: an energy storage element having two electrodes; twoterminals extending from the element for allowing electrical connectionto the electrodes; and a housing for containing the element, theterminals and an electrolyte for allowing ionic conduction between theelectrodes, the housing being folded.
 80. A device according to claim 79wherein the housing is folded along a fold line that is at or adjacentto and substantially parallel with and edge of the element whereby theelement lies on one side of the fold line and a folded portion lies onthe other side of the fold line.
 81. A device according to claim 79wherein the housing is folded along more than one spaced apart foldlines and the respective folded portions overlie the element.
 82. Adevice according to claim 79 wherein the housing is folded along morethan one spaced apart fold lines and the respective folded portions donot overlie each other.
 83. A device according to claim 81 or claim 82wherein the folded portions are folded toward each other.
 84. A deviceaccording to claim 79 wherein the fold line passes through a terminal.85. A device according to claim 79 including two folded portions havingrespective openings that are covered and sealed by respective terminalswhereby the terminals are electrically accessible via the respectiveopenings.
 86. A device according to claim 85 including at least onecontact that is secured to one of the terminals through the respectiveopening whereby the contact is sandwiched between the folded portion andthe element.
 87. A composite energy storage component including two likedevices claim 79 wherein the terminals extend from a respective one ofthe electrode of the devices and the other of the electrodes of thedevices being adjacent to each other and electrically connected.
 88. Acomponent according to claim 87 wherein all the folded portions aredisposed intermediate the elements to define a folded configuration forthe component.
 89. A component according to claim 87 including amounting member for retaining the component in the folded configuration.90. A component according to claim 87 wherein the other of theelectrodes of the devices are electrically connected via one or morelike devices of claim
 79. 91. An energy storage device including: ahousing; an energy storage element being sealingly contained within thehousing; a mount that extends about and captively engages the housing;and two terminals that extend from the energy storage element andterminate outside the housing for allowing external electricalconnection to the element.
 92. A device according to claim 91 whereinthe mount includes a support frame for receiving the housing and atleast one locking element that extends from the frame for captivelyengaging the housing within the support frame.
 93. A device according toclaim 92 wherein the locking element is integrally formed with the frameand is deformed into abutment with the housing to captively engage thehousing within the support frame.
 94. A device according to claim 91wherein the housing is retained within the frame in a foldedconfiguration.
 95. An energy storage device including: a folded housing;at least one energy storage element being sealingly contained within thehousing; a mount that extends about and captively retains the housing inthe folded configuration; and two terminals that extend from the energystorage element and terminate outside the housing for allowing externalelectrical connection to the element.
 96. An energy storage deviceincluding: a plurality of first electrodes having respective firstsurfaces of a first area; a plurality of second electrodes havingrespective second surfaces of a second area, the electrodes beingstacked such that the second surfaces are opposed to respective firstsurfaces whereby the opposed surfaces collectively define respectiveoverlapped portions having a third area that is less than the first andthe second areas; a separator having a first edge and a second edgetransversely spaced apart from the first edge, the separator beingdisposed between the surfaces and extending across at least theoverlapped portion for maintaining the electrodes in a spaced apartconfiguration, wherein the first electrodes each include a first tabthat extends beyond the first edge and the second electrodes eachinclude a second tab that extends beyond the second edge; a housing forcontaining the electrodes, the separator and an electrolyte for allowingionic conduction between the electrodes; and two terminals beingrespectively electrically connected to the first and the second tabs andbeing accessible from outside the housing for allowing externalelectrical connection to the electrodes.
 97. A device according to claim96 wherein the first and the second surfaces include respective carboncoatings at least in the overlapped portion.
 98. A device according toclaim 96 wherein the first and the second electrodes are longitudinallyextending sheet electrodes.
 99. A device according to claim 96 whereinthe electrodes are stacked together.
 100. A device according to claim 96wherein the electrodes are wound together about a transverse windingaxis.
 101. A device according to claim 99 wherein, in the stackedconfiguration, each electrode is substantially planar.
 102. A deviceaccording to claim 96 wherein the first tabs are connected together todefine a first collective tab that is disposed beyond the first edge andthe second tabs are connected together to define a second collective tabthat is disposed beyond the second edge, wherein the first and thesecond collective tabs are electrically connected to respectiveterminals.
 103. A device according to claim 102 wherein the first andthe second edges are parallel and the first and the second collectivetabs extend outwardly and away from each other.
 104. A device accordingto claim 96 wherein the separator includes a plurality of separateporous sheets.
 105. A device according to claim 104 wherein the sheetsare joined at adjacent peripheral edges.
 106. A mount for an energystorage device, the mount including: a frame member having an openingfor receiving the device; and one or more tabs extending from the framemember for selectively preventing progression of the device through theopening.
 107. A mount according to claim 106 wherein the tabs aremovable between an open configuration and a closed configuration inwhich the device is respectively allowed and prevented from movementthrough the opening.
 108. A mount according to claim 106 wherein thetabs are integrally formed with the frame and are deformed into the openand the closed configurations.
 109. A mount according to claim 108wherein the deformation is reversible.
 110. A housing for an energystorage device having at least one terminal, the housing including: afirst plastics layer for enclosing the device and which is bonded to theterminal over a contact area; a barrier layer exterior to the plasticslayer; a second plastics layer exterior to the barrier layer; an openingthrough the layers for allowing access to the terminal, wherein theterminal covers the opening and the contact area surrounds the opening;and a filler material intermediate the first plastics layer and theterminal and spread over at least the contact area.
 111. A terminal foran energy storage device, the terminal including: a conductive contactsurface; a first plastics layer for abutting and sealingly engaging thesurface; a barrier layer exterior to the plastics layer; a secondplastics layer exterior to the barrier layer; and an opening through thelayers for allowing electrical access to the surface.
 112. A housing foran energy storage device having at least one terminal, the housingincluding: a first plastics layer for enclosing the device and which isbonded to the terminal over a contact area; a barrier layer exterior tothe plastics layer; a second plastics layer exterior to the barrierlayer; an opening through the layers for allowing access to theterminal, wherein the terminal spans the opening; and a filler materialintermediate the first plastics layer and the terminal and spread overat least the contact area.
 113. An energy storage device including: anenergy storage cell; a housing for containing the cell, the housinghaving two abutted portions that are sealed together, wherein theabutted portions are of substantially uniform collective thickness; andtwo terminals connected to the cell for allowing external electricalconnection with the cell.
 114. A device according to claim 113 includingtwo openings that are covered by the respective terminals and twosealing portions that surround and are adjacent to the openings.
 115. Adevice according to claim 113 wherein the terminals are planar and thesealing portions overlie and are sealingly engaged with the terminals.116. A device according to claim 115 wherein that sealing engagement iseffected by heat.
 117. A device according to claim 113 wherein thehousing includes a barrier sheet having a first peripheral edge and asecond peripheral edge, wherein the sheet is folded upon itself so thatthe peripheral edges define the respective abutted portions. 7.(Currently amended) An energy storage device according to claim 5 orclaim 6 wherein the opposed faces are abutted and joined together alongless than the entirety of each edge.
 54. (Currently amended) A methodaccording to claim 52 or claim 53 wherein the heat sealing or weldingextends longitudinally across substantially all the slot.
 55. (Currentlyamended) A method according to claim 52 or clam 53 wherein the heatsealing or welding extends transversely across substantially all theslot.
 56. (Currently amended) A method according to claim 52 or claim 53wherein the heat sealing is affected at two or more spaced apartlocations in the slot.
 83. (Currently amended) A device according toclaim 81 or claim 82 wherein the folded portions are folded toward eachother.